Digital Port Menu - Ametek 7270 Instruction Manual

Chapter 5, FRONT PANEL OPERATION

5.3.33 Digital Port Menu

5-54
EXT ADC1 MON
When set to the EXT ADC1 MON setting the corresponding DAC connector on
the rear panel of the instrument outputs a voltage representing the voltage at the
rear-panel ADC1 input connector.
SYNC OSC
When set to the SYNC OSC setting the corresponding DAC connector on the
rear panel of the instrument outputs a voltage representing the sinusoidal
waveform applied to the first in-phase demodulator. If the reference mode is
external, this allows generation of a sinusoidal signal that is phase locked, and
with adjustable phase relationship, to it.
Pressing the Previous Menu key returns control to Main Menu 2.
When Main Menu 2 is displayed, pressing a key adjacent to the Digital Port menu
item accesses the Digital Port menu, shown in figure 5-41.
The Digital Port menu allows the operating mode of each of the eight pins of the
DIGITAL I/O connector on the rear panel of the instrument to be set and its logic
status to be set and read. This port may be used for controlling or reading the status
of external equipment, for example the switching of heaters or attenuators, via a
suitable user-supplied external interface circuit.
Each of the eight pins is configured as an input or output by the Bit direction digits;
when the digit is a I, the corresponding bit is an input; when it is O it is an output.
For those bits configured as outputs, the Output value digits define whether they are
high (value = 1) or low (value = 0)
To change a given bit, use the
until it is under the digit to be changed. Set the required status, either 1 or 0, by using
the numeric keys.
DECIMAL OUTPUT
This control offers an alternative way of changing the output value. The number is
the decimal equivalent of the displayed output value bit pattern, and consequently
Figure 5-41, Digital Port Menu
, , and to move the underscore (_) cursor